A microfluidic platform for continuous monitoring of dopamine homeostasis in dopaminergic cells

Yue Yu,Richard P S De Campos,Siddharth Sadanand,Dimitar L Krastev,Aaron R Wheeler,Yen Leung,Seolim Hong

doi:10.1038/s41378-019-0049-2

Yue Yu, Richard P S De Campos + Show 5 more

Open Access

https://doi.org/10.1038/s41378-019-0049-2

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Abstract

Homeostasis of dopamine, a classical neurotransmitter, is a key indicator of neuronal health. Dysfunction in the regulation of dopamine is implicated in a long list of neurological disorders, including addiction, depression, and neurodegeneration. The existing methods used to evaluate dopamine homeostasis in vitro are inconvenient and do not allow for continuous non-destructive measurement. In response to this challenge, we introduce an integrated microfluidic system that combines dopaminergic cell culture and differentiation with electroanalytical measurements of extracellular dopamine in real-time at any point during an assay. We used the system to examine the behavior of differentiated SH-SY5Y cells upon exposure to four dopamine transporter ant/agonists (cocaine, ketamine, epigallocatechin gallate, and amphetamine) and study their pharmacokinetics. The IC50 values of cocaine, ketamine, and epigallocatechin gallate were determined to be (average ± standard deviation) 3.7 ± 1.1 µM, 51.4 ± 17.9 µM, and 2.6 ± 0.8 µM, respectively. Furthermore, we used the new system to study amphetamine-mediated dopamine release to probe the related phenomena of dopamine transporter-mediated reverse-transport and dopamine release from vesicles. We propose that this platform, which is the first platform to simultaneously evaluate uptake and release, could be useful to screen for drugs and other agents that target dopaminergic neurons and the function of the dopamine transporter. More broadly, this platform should be adaptable for any application that could benefit from high-temporal resolution electroanalysis combined with multi-day cell culture using small numbers of cells.

Highlights

The maintenance of dopamine (DA) homeostasis in the nervous system is critically important as DA overexposure can lead to excitotoxicity and neuron death[1]
Numerous microchannel-based microfluidic platforms have been used to evaluate neurotransmitter release from neuronal cells[20,21], but these platforms have not been applied to this problem; we are unaware of any system that is capable of evaluating both neurotransmitter uptake and release
We sought to combine (a) and (b) into a single, integrated unit known as a “cell-culture/ electroanalytical sensor” that allows for the continuous monitoring of DA homeostasis

Summary

Introduction

The maintenance of dopamine (DA) homeostasis in the nervous system is critically important as DA overexposure can lead to excitotoxicity and neuron death[1]. SH-SY5Y cells were seeded, cultured, and differentiated on c-e-sensors as described in the supplementary information, and DMF and passive dispensing were used to automate all experiments described below.

Results

Conclusion